Pervasive beliefs regarding curricular reform and integration have flourished among medical students, faculty members and medical school administrators. These concepts have extensively impacted the reform process, sometimes by resisting the reforms and sometimes by diverting the curriculum from its planned objectives. In the current paper, we have tried to address the challenges of integration in MD program by looking at the existing literature and the experience of the international universities.We collected the questions frequently asked during the curricular reform process. We, then, evaluated them, and selected 5 main ideas. In order to find their answers, we searched the literature using these keywords: integration, reform, and undergraduate medical curriculum.The findings are discussed in five sections: 1) Reform is not equivalent to integration, 2) Integration can be implemented in both high school and graduate programs, 3) Organ-system based integration is not the only method available for integration, 4) Integration of two phases (basic sciences and physiopathology) can be considered but it is not mandatory, 5) Integration does not fade basic sciences in favor of clinical courses.It seems that medical education literature and prior experience of the leading universities do not support most of the usual concepts about integration. Therefore, it is important to consider informed decision making based on best evidence rather than personal opinions during the curricular reform process.